Field of the Invention
The invention relates to a connection terminal with a clip housing for fixing a modular terminal block which has several modular terminals in an opening of a housing wall. In addition, the invention relates to a unit having two connection terminals and several modular terminals which are located next to one another.
Description of Related Art
Electrical modular terminals have been known for decades and are used millions of times in the wiring of electrical systems and devices. The terminals are often locked onto mounting rails which, for their part, several terminals can be arranged in a switchgear cabinet. But, in addition, the modular terminals can also be mounted alone or in general severally as a modular terminal block in a wall opening, in particular in an opening of a switchgear cabinet wall. This has the advantage that one side of the terminals, the operator side, is accessible from outside the switchgear cabinet, without the switchgear cabinet having to be opened, and only the other side of the terminal, the connection side, is accessible only with the switchgear cabinet opened.
In modular terminals, mostly screw-type terminals or tension spring terminals are used as conductor connecting elements. The clamping principle in tension spring terminals is similar to that of screw technology. While in the screw-type terminal a tension sleeve pulls the conductor against the busbar by activating the terminal screw, in the tension spring terminal its task is assumed by the tension spring. In addition, however, also insulation piercing terminals or torsion spring terminals can be used.
Electrical modular terminals are generally connecting terminals so that they have at least two conductor connecting elements which are electrically connected to one another via an electrically conductive connecting bar, the busbar. In addition to this basic type of modular terminals, which is also often called a feed-through terminal, there are a host of different modular terminal types which are adapted especially to the respective applications (compare Phoenix Contact Catalog Modular Terminal CLIPLINE 2011, pp. 2-11). Examples here are protective conductor terminals, isolating blade terminals, and installation terminals.
In switching, measurement and control technology, feed-through terminals with an isolating capacity are the standard. The isolating possibility which is implemented in the electrical modular terminal, i.e., the isolating point which is provided in the busbar, makes it possible to plug different plugs with different functions into the terminal housing of the modular terminals which then make contact with the busbar at the isolating point. In addition to simple isolating plugs or through connectors, in particular, test plugs can also be used which can have special components and which enable checking of the proper operation of the circuit which is connected to the modular terminal. Since electrical modular terminals are generally made disk-shaped, they are generally mated to several other electrical modular terminals to form a modular terminal block. Then, a number of test plugs which corresponds to the number of modular terminals can be plugged into this modular terminal block.
A device is disclosed in German Patent Application DE 10 2005 025 108 B3 for testing of a protective, measurement or counting apparatus, for example, a line protective relay, which has a pole strip which can be connected to the electrical apparatus with several successively arranged pole openings and a plug block with a number of pole tongues which corresponds to the number of pole openings. An individual pole strip module of the pole strip consists of a housing in which there are two jacks for connection of lines and spring-loaded contact clips which are connected to the jacks. The pole tongue of one plug can make contact with the two contact clips, the pole tongue of the plug having two pole bars which are separated from one another by an insulating bar. The insulating bar together with the corresponding pole openings in the pole strip module forms polarization which ensures that only one plug with a certain pole tongue can be inserted into a certain pole opening of a pole strip.
When the plug or the pole tongue has not been plugged into the pole strip, the two contact clips make contact with one another so that the two jacks are connected to one another in an electrically conductive manner and current can flow via a connected pole strip. If the plug with its pole tongue is inserted completely into the pole opening, the two contact clips are electrically separated from another and the current flow is routed via the plug so that a test process can be carried out.
German Patent Application DE 10 2006 052 894 A1 and corresponding U.S. Pat. No. 7,666,037 B2 disclose a modular terminal, a test plug and a test terminal block having a plurality of modular terminals which are located next to one another and a corresponding number of test plugs, the individual modular terminals and the individual test plugs being similar in basic principle to the pole strip modules and pole plugs which are known from German Patent Application DE 10 2005 025 108 B3.
In order to ensure defined contact states when the test plug is plugged into the test opening, in these known electrical modular terminals the busbars are made such that they form two contact regions which are located in succession in the insertion direction of one test plug. Forming a defined second contact region which is located in the insertion direction of the contact plug upstream of the first contact region ensures that when the contact plug is inserted first a reliable electrical connection between the contact plug and the two busbars is formed before the first contact region is opened as the contact plug continues to be inserted, as a result of which the two busbars are then electrically isolated from one another.
It is common to the above described known modular terminals and test terminal blocks that the two busbars make contact with one another so that the conductor connecting elements are connected to one another in an electrically conductive manner if a plug has not been plugged into the modular terminal. Conversely, if a plug has been (completely) plugged into the modular terminal, the contact region is interrupted so that the conductor connecting elements are also electrically isolated from one another.
In addition to these modular terminals and test terminal blocks, test isolating blocks are also known from practice, in particular those from the Russian company Cheaz which are very common in Eastern Europe and Russia, in which the elastic contact sections of the busbars which together form an elastic contact region are spaced apart from one another and are connected to one another in an electrically conductive manner only when a plug of a service plug or test plug is plugged into the contact region. The electrically conductive connection between the contact sections and between the busbars takes place via the inserted plug which for this purpose has two interconnected contact sections which make contact with the contact sections of the busbars when the plug has been plugged in.
In these test isolating blocks, the conductor connecting elements assigned to one another are thus only connected to one another in an electrically conductive manner when a corresponding service plug is plugged into the modular terminal or into the terminal block. These modular terminals or terminal blocks are used in particular for connection of current transformers. One important operating feature is that the current transformers are short circuited as soon as the test plug or service plug is pulled out of the modular terminal or the terminal block. To do this, in the known test isolating blocks, there are jumper plugs via which at least two adjacent busbars are connected to one another in an electrically conductive manner so that the assigned conductor connecting elements are short circuited. In this way, then, the current transformers which are connected to the conductor connecting elements are also short circuited.
In these test terminal blocks which are known from the prior art, the jumper plugs ensure an electrically conductive connection between adjacent contact sections or busbars. This cross bridging is automatically interrupted when a test plug or service plug is plugged in, at the same time the contact sections which are assigned to one another being connected to one another in an electrically conductive manner via the plug.
Regardless of how the modular terminals are made, in particular, whether as connecting terminals or feed-through terminals with an isolating possibility and regardless of whether the busbars make contact in feed-through terminals with an isolating possibility and thus the conductor connecting elements are connected to one another in an electrically conductive manner when a plug is plugged into the modular terminal, or whether the busbars are spaced apart from one another and are only connected to one another in an electrically conductive manner when a plug has been plugged into the contact region, these modular terminals are often arranged severally next to one another and are mechanically connected to one another so that together they form a modular terminal block.
In contrast to “normal” modular terminals, especially the above described test terminals or test terminal blocks are often not locked on a mounting rail, but in an opening of a housing wall, for example, a switchgear cabinet door or a switchgear cabinet wall.
In this connection, it is known for two-part terminals, for example, from German Patent DE 36 13 681 C1, that the two parts of the electrical terminal have catch elements which correspond to one another and which, when the two terminal parts are inserted into one another, interlock with one another and prevent isolation of the two terminal parts against the insertion direction. To do this, the two parts of the terminal must be plugged in the opposite direction through the wall opening in the housing wall so that the housing wall is clamped between the parts of the terminal. The disadvantage of this type of mounting of a terminal in a wall opening is that, on the one hand, the terminal itself must be made in two parts, on the other, the mounting and dismounting of the terminal in the wall opening takes place from the two sides.
German Patent DE 198 01 260 C2 discloses a modular terminal in which a one-piece terminal housing is routed through the wall opening up to a stop and then a notch lever is slipped onto the part which has been routed through the wall opening. The notch lever in doing so interlocks with two opposite sides of the housing so that the housing wall is fixed between the stop on one side and the notch lever on the other side. In doing so the housing wall must be accessible on both sides for mounting.
German Utility Model DE 202 00 974 U1 discloses a modular terminal in which the one-piece terminal housing is inserted through the wall opening of a housing, when the terminal housing is pushed through the wall opening spring catches provided on two opposite sides of the housing each being displaced back by one inside edge of the wall opening. For final fixing of the terminal in the wall opening, the spring catches must be prevented from springing back again by a blocking slide which can only be operated from the inside of the housing, while the terminal must first be inserted from the outside of the wall opening so that access to the two sides of the housing wall during mounting is also necessary here.